Printers and recorders of various types have been developed which employ a stream of ink droplets that are directed upon a print medium. The ink is ejected through a small nozzle as a result of the action of a transducer. A chamber is formed that is partially enclosed by a flexible diaphragm backed by a piezoceramic to form a chamber. A channel leads from the chamber to the opening and another channel leads to the chamber so that ink may be supplied thereto. A small charge is applied to the piezoceramic to alter its length and thereby cause a drop of ink to be ejected from the chamber and out the nozzle. In prior devices, the transducer was composed not only of a piezoceramic but also included a diaphragm layer between the chamber and the piezoceramic. The diaphragms are made of materials such as metal or ceramic. The thicknesses of the layers are selected to achieve the required deflection for a given applied voltage. An example of such a combination is described in U.S. Pat. No. 3,871,004. In another device, the transducer is made of a pair of piezo-electric plates with a conductive film sandwiched between the two plates. Such a device is described in U.S. Pat. No. 3,946,398.
Although prior systems have worked substantially well, improvements are always sought. One goal consistently pursued is to have the nozzles of the ink jet printer as close to one another as possible, in order to obtain higher resolution printing. The barrier in having nozzles close together is the minimum space requirement of each chamber. Various compensatory designs have been developed. One such is to have more rows of nozzles whereby the nozzles are staggered relative to one another. One disadvantage on this approach is that synchronization is required between the enabling of the piezoceramic elements and movement of the medium being printed. Another way of attempting to increase the density of openings is to have canalized chambers as opposed to circular chambers. One problem with this configuration is a reduction in performance. Another approach is to fan out the chambers. The disadvantage with this configuration is that the chambers are further removed from the openings diminishing the emission rate.
In a copending application assigned to the assignee of this application and filed Feb. 11, 1985 with the title "SINGLE ELEMENT TRANSDUCER FOR AN INK JET DEVICE" and Ser. No. 700,582, a one component transducer is described. In this copending application, the transducer has a spherical configuration that is formed.